Function mu_plus_lambda 

pub fn mu_plus_lambda<B: Backend>(
    parents: Tensor<B, 2>,
    parent_fitness: &[f32],
    offspring: Tensor<B, 2>,
    offspring_fitness: &[f32],
    mu: usize,
    device: &B::Device,
) -> (Tensor<B, 2>, Vec<f32>)

(μ + λ) replacement: merge the μ parents with the λ offspring and keep the μ lowest-fitness members overall.

Panics

Panics if mu > parent_fitness.len() + offspring_fitness.len() (the underlying truncation cannot select more winners than the combined pool contains).